The biochemical effects of ozone on red blood cells will be studied primarily as a model to aid in the understanding of the reaction of ozone with cells of the lung. The studies are designed to show whether the first effect of ozone on the cellular membrane is on the protein or the lipid component. It is also proposed to determine the proportion of ozone that can pass the cellular membrane and have an effect in the cell. These results with a relatively simple and relatively well understood cell (the red blood cell) will be applied to studies of the lung. In one series of experiments specific lung cell types will be exposed to ozone and the effect on enzymes of lipid metabolism and peroxide detoxification will be measured. Lipid synthesis is particularly susceptible and will be studied in detail. In a second series, animals breathing ozone will have precursors of lipids injected in the blood stream and the lipid synthesis in the lungs subsequently measured. In this way we can test results obtained in vitro, under more physiological conditions.